The candidate applies for Phase I RSDA award to facilitate transition to a principal investigator position (Assistant Professor) at a new research organization. This award will allow the candidate to fully develop a strong research program supported by NIH funded grants. Specialized gamma-delta T cells reside in various epithelial tissues (skin, gut, reproductive organs) where they extend long cellular projections to recognize stress-affected and cancerous cells. Specific activation of skin-resident dendritic epidermal T cells (DETCs) through the gamma delta T cell Receptor (gdTCR) is important for wound healing, cytotoxicity against skin tumors, and regulation of topical dermatitis. gdTCR forms different complexes with signal transducing CDS chains and FcRgamma chains and little is known how such complexes rearrange and interact with the as yet unknown antigen. Recently, we established a method to study protein-protein interactions in immunological synapses formed by alpha-beta T cells using Forster resonance energy transfer (FRET) imaging. Thus far, we will employ combination of sub-cellular live FRET imaging and protein biochemistry to better understand how the molecular interactions within gdTCR regulate recognition of stress and cancer antigens by DETCs. Specifically, in Aim 1 we will determine if the replacement of CD3zeta by FcRgamma within the gdTCR complex is dynamically regulated in multiple intercellular contact sites of DETCs. Our Aim 2 is to locate the molecular determinants in the structures of CD3zeta and FcRgamma which regulate incorporation of each chain into the gdTCR complex in DETCs.